1. Technical Field
The present invention relates to angle-adjustable solar energy street lamp structures and, more particularly, to a solar energy street lamp structure with an adjustable angle for use with street lamps.
2. Description of Related Art
With crude oil prices continuously on the rise worldwide due to the gradual depletion of petroleum fuel, and with global greenhouse gas emissions being under regulation after the Kyoto Protocol was signed, almost all major countries in the world have devoted considerable resources to the research of alternative energy sources such as electricity generated by wind power or hydraulic power, biodiesel, solar energy, and so on. Of the various technologies of alternative energy sources, solar energy technology is the most highly developed.
Solar energy is used mainly by converting light energy from the sun into electric power and is presently applicable to solar energy vehicles, indoor lighting, outdoor bulletins, and so forth. Now that street lamps are commonly seen in our daily life and are exposed to the sun for a long time, it is very suitable for street lamps to be powered by solar energy. Besides, solar energy street lamps may also solve the problem of inconvenient power cable deployment in remote areas.
Taiwan Patent No. M283111 discloses a “Solar Energy Street Lamp” comprising a lamp holder, a lighting device, a rechargeable battery, and a photovoltaic panel. The photovoltaic panel absorbs solar energy, converts the absorbed solar energy into electric power, and delivers the electric power to the rechargeable battery. The rechargeable battery then supplies necessary electric power to the lighting device and thereby drives the lighting device to emit light.
However, solar energy street lamps are mostly located along urban streets, where sunlight may be blocked by nearby buildings. In such cases, the solar energy street lamps are exposed to the sun only for part, but not all, of the daytime hours such that the solar energy absorbed by the solar energy street lamps is insufficient to generate enough electric power for sustaining light emission by lighting devices of the solar energy street lamps. Consequently, nighttime illumination on the streets is compromised.